Help with first M@g LED Mod.....

Ok gang I'm gona do my first LED mod on a M@g body and I need some suggestions as to which way to go because I know nothing about LED's except they cost more than bulbs and they can easily be killed…… I have the HotLips for the C & D body, a TWAK on the way from Wayne that should be here soon. I have all but worn the hinges off the door at the Sandwich shop and still don't have a clue as which one to go with. Any suggestions on a battery sandwich combo platter would be greatly appreciated.



Host:
M@g 2C/4C or 2D/3D

Battery:
CR123's, C or D cell's

Run Time:
Around 3 hours regulated.

Brightness:
Better than what I started with.

Sway,
I have built a M@g 2D with parts from Wayne myself. It's particular job in life is a frame mounted light for my bicycle. It ended up a very piercing beam that is quite narrow but has a loooooong throw.
I use a Luxeon "1.2 watt" ranked R2H which, as testing indicates makes it a Luxeon III TWAK. Anyway, I used the Madmax+ board (not the drop-in mod) It motivates the R2H with 800-900mA being fed by two D cells. My battery life is around 8 to 10 hours although I am not exactly sure (I won't ride for 10 hours of darkness straight. /ubbthreads/images/graemlins/banghead.gif )
When I build another one, I will use the Hotlips heatsink so I can have some adjustability (like you have) A BB700 would fit my needs better as it gives a nice even output through the life of the batteries. That should also boost the battery life a few hours to 10 to 12 hours. Now for those UWAK or VWAK Luxeon III's to come out.
Mount the BB700 under the heatsink offset to the side of the sink. Use thermal epoxy and glue it to the bottom of the heatsink before you start any soldering. After the epoxy has dried, solder the wires to the bottom of the board so the heat of soldering will be sinked and not burn up the components.
Good luck!

Sounds very nice, do you happen to know what it cost you overall? Thanks

-Mike

Hi BentHeadTX,

That sounds like a good mod in the 2D, I will have to look at the BB700 and the life time of the D cells makes it even more interesting, I'm not looking for a flame thrower just something better than what I started with in the M@g host.

Thanks Sway /ubbthreads/images/graemlins/thumbsup.gif

A nice, easy and inexpensive M@g mod is to use a 2D host. Get some 1", I believe it is, pvc pipe and cut it down so that you can fit 3C's into the 2D light. You have to trim the stock spring so that it sits all the way at the bottom of the battery cover and remove the anodizing so that the spring can make contact.

With this battery configuration, all you need is a heatsink. Just direct drive it with a 1 or 3W and you'll have a nice 1A luxeon light. No circuits needed.

Wayne didn't have anymore of his "washer" heatsinks, so I just got some washers, epoxied three of them together with AA and used that. It's a really simple mod and goes together quickly. The funny thing is that my 2D M@g is the brightest 1W light I have and cost the least.

BTW, you can do a search here on modding the M@g. Lots have done it. Whether you go with a trimmed down stock reflector or an optic, is up to you. You can get as extravagent with the mod as you wish, from custom reflectors to betters lenses.

The total cost of my last M@g mod was about $18 plus the cost of the M@g.

OK let me see if I got this right, if I go with direct drive 3 C or D instead of a sandwich don't I need to run a resistor in the path somewhere? If so what with the TWAK III /ubbthreads/images/graemlins/dedhorse.gif

Even better with the TWAK III, since it's spec'ed to run at 1A.

Sway, if it would make you feel better to use a resistor, by all means do so. I'm thinking maybe 1.2 ohms of resistance. Someone chime in if I'm wrong, but:

The Vf of the TWAK is around 3.51 -3.75v. So if you're feeding them with 3 cells, say 4.5v. So your voltage drop across the resistor would be 4.5 - 3.6(middle of the road value) = .9v So, .9/1.2 = .75 or 750 mA. Or you could just use a 1 ohm resistor for around 900mA. Well within spec.

I think my math is right. The above is only to be used as a starting point for reference. Anyway, the batts drop voltage pretty quickly. I just run mine in DD. I haven't had any problems, YET.